無病無痛，沒有任何交通或人為意外的話，人類是否會進入不死永生狀態呢？783Please respect copyright.ＰＥＮＡＮＡ2iVYQhIKAu
783Please respect copyright.ＰＥＮＡＮＡuPT8iAFm2d
答案是，不會。783Please respect copyright.ＰＥＮＡＮＡlXsgLM2YrM
783Please respect copyright.ＰＥＮＡＮＡ99OXrwbVQE
箇中的原因，就是在於染色體亦即是DNA的運作機制之上。783Please respect copyright.ＰＥＮＡＮＡDq6fkk8s1w
783Please respect copyright.ＰＥＮＡＮＡdas3BPQrxr
783Please respect copyright.ＰＥＮＡＮＡBZCPsHRML7
（圖1）正常人體細胞分裂的時候，染色體的長度會越來越短。783Please respect copyright.ＰＥＮＡＮＡinqp8eWEj0
783Please respect copyright.ＰＥＮＡＮＡXcTfIoda0V
783Please respect copyright.ＰＥＮＡＮＡ4dtCvr6fl2
783Please respect copyright.ＰＥＮＡＮＡDNGrewzMx8
（圖2）染色體的頂端區域，我們稱之為Telomere。正常細胞分裂後，Telomere的長度便會越來越短，所以導致染色體的總長度亦會有所減少。783Please respect copyright.ＰＥＮＡＮＡ1gvzurvHx4
783Please respect copyright.ＰＥＮＡＮＡsrkf44KIdD
783Please respect copyright.ＰＥＮＡＮＡVTO3VN3vSk
（圖3）而幹細胞進行分裂的時候，則會有著Telomerase的協助，導致Telomere的長度便並不會有所減少。783Please respect copyright.ＰＥＮＡＮＡPXZqEVin6H
然而，當幹細胞變成正常細胞後，Telomerase的功能便會消失。783Please respect copyright.ＰＥＮＡＮＡ7uEmN4PrrG
783Please respect copyright.ＰＥＮＡＮＡKaZNBegBCB
783Please respect copyright.ＰＥＮＡＮＡiDKJ6zYer1
783Please respect copyright.ＰＥＮＡＮＡRaHmyrUp6g
（圖4）當Telomere長度削減到一定程度的時候，細胞便會自行啟動機制滅亡，又或者陷入衰老(Senescence)狀態。783Please respect copyright.ＰＥＮＡＮＡRvzANldTdd
783Please respect copyright.ＰＥＮＡＮＡLtJln7r0HZ
細胞滅亡或衰老的話，器官的功能便會衰退，最後亦會支撐不住，無法正常運作，促成死亡。783Please respect copyright.ＰＥＮＡＮＡpQGg9zGYq3
783Please respect copyright.ＰＥＮＡＮＡyr9eGPtIQr
783Please respect copyright.ＰＥＮＡＮＡ0tVSFNfZqc
你可能會問，現在科技如此倡明，那麼我們只要學習幹細胞的那一套方式，動用外力重啟Telomerase功能，那不就能踏入永生嗎？783Please respect copyright.ＰＥＮＡＮＡgqu6qqH4PQ
783Please respect copyright.ＰＥＮＡＮＡa089ok4WCm
這個思路並沒有錯，只不過代價就是會增加患癌的風險。783Please respect copyright.ＰＥＮＡＮＡPaiiLsWM0N
783Please respect copyright.ＰＥＮＡＮＡJXUWE97yZX
事實上，不少癌細胞的特徵就是Telomere長度非常之短，但又有著一定水平的Telomerase功能穩定維持著Telomere的長度，逃避進入滅亡的命運。783Please respect copyright.ＰＥＮＡＮＡVdTuyvKSwW
783Please respect copyright.ＰＥＮＡＮＡFiT8bk3gJq
另一方面的想，如果細胞真的是踏入「永生」狀態的話，終有一天無可避免會累積各種的DNA變異，促成癌細胞的誕生。783Please respect copyright.ＰＥＮＡＮＡy5ytr7YWKe
783Please respect copyright.ＰＥＮＡＮＡ7K4TG9dAi3
（圖5）既然Telomere對細胞的壽命有著重要影響的話，那麼一些較為長壽的物種是否擁有較長的Telomere呢？783Please respect copyright.ＰＥＮＡＮＡm13esxRw85
783Please respect copyright.ＰＥＮＡＮＡxvZNEiUfmQ
科學家比較各物種的Telomere後（Ref1)，發現海豚的起始Telomere長度比人類高出6倍以上，但壽命長度始終是人類佔優。783Please respect copyright.ＰＥＮＡＮＡPwIWTn1W97
783Please respect copyright.ＰＥＮＡＮＡbP67LoVTs8
783Please respect copyright.ＰＥＮＡＮＡLFQuHywxSK
反而，決定物種壽命長度的其中一種因素，則是Telomere衰減的速度；783Please respect copyright.ＰＥＮＡＮＡZL8G54ccoI
Telomere衰減的速度只是一個參考性的指標，並非絕對。物種的大小、新陳代謝機制的不同等等均會對壽命長度有著影響。783Please respect copyright.ＰＥＮＡＮＡ6IMsNLxKGS
783Please respect copyright.ＰＥＮＡＮＡBfS5H4aF0F
人類每年約會減少71單位Telomere的長度，最高壽命為120歲。783Please respect copyright.ＰＥＮＡＮＡJaZixYOwC9
而老鼠每年會減少7000單位Telomere長度，最高壽命為5歲。783Please respect copyright.ＰＥＮＡＮＡJA941XQwUk
783Please respect copyright.ＰＥＮＡＮＡcywcsmpokr
人類：每年減少71；120歲783Please respect copyright.ＰＥＮＡＮＡlCy220v0iL
大象：每年減少109；66歲783Please respect copyright.ＰＥＮＡＮＡe99ZJFuXq2
紅鸛：每年減少105；60歲783Please respect copyright.ＰＥＮＡＮＡmXHswDl8oL
海豚：每年減少766；52歲783Please respect copyright.ＰＥＮＡＮＡoaAqwaqFIs
兀鷲：每年減少209；41歲783Please respect copyright.ＰＥＮＡＮＡTNK33cCLhy
海鷗：每年減少771；25歲783Please respect copyright.ＰＥＮＡＮＡQtF18uVAsS
馴鹿：每年減少531；22歲783Please respect copyright.ＰＥＮＡＮＡ70SpBubTtM
山羊：每年減少363；21歲783Please respect copyright.ＰＥＮＡＮＡskH5ymNwwb
老鼠：每年減少7000；5歲783Please respect copyright.ＰＥＮＡＮＡWI0a5Zq5NO
783Please respect copyright.ＰＥＮＡＮＡecsWAey5MW
783Please respect copyright.ＰＥＮＡＮＡ9YVSSXf46b
龜又是每年減少幾多呢？有待有心人發掘。783Please respect copyright.ＰＥＮＡＮＡIMcWkuULdy
783Please respect copyright.ＰＥＮＡＮＡZhFkVKiAEK
783Please respect copyright.ＰＥＮＡＮＡQMxBvLwAzp
如果想我快啲出文的話，請入去Penana網站科普專欄–薯不揀單俾一個like以及Bookmark，這對我非常之重要。783Please respect copyright.ＰＥＮＡＮＡHt1VL1AL4A
783Please respect copyright.ＰＥＮＡＮＡ1YtNkO0MWJ
Link: https://www.penana.com/story/66244/%E7%A7%91%E6%99%AE%E5%B0%88%E6%AC%84-%E8%96%AF%E4%B8%8D%E6%8F%80%E5%96%AE/toc783Please respect copyright.ＰＥＮＡＮＡ8XIIoUKPgK
783Please respect copyright.ＰＥＮＡＮＡ3SLcq7F1w8
同時亦可以在Penana網站裡按「買一嚿/半嚿薯仔」，以課金的方式推動我繼續搜羅資料寫文，多謝。783Please respect copyright.ＰＥＮＡＮＡJbBbroBWlA
783Please respect copyright.ＰＥＮＡＮＡhWM5CVte6x
Link:783Please respect copyright.ＰＥＮＡＮＡmrslcXewf5
https://www.penana.com/user/27349/%E8%96%AF%E4%BB%94%E8%81%9E%E8%8C%B1%E8%8E%89/portfolio783Please respect copyright.ＰＥＮＡＮＡY1qGt9VFne
783Please respect copyright.ＰＥＮＡＮＡoTmMvy8qM6
783Please respect copyright.ＰＥＮＡＮＡ20BBGM1r9y
有興趣接收科學資訊的話，歡迎follow IG: potatopigtongue。783Please respect copyright.ＰＥＮＡＮＡ8hbeXrhQMG
783Please respect copyright.ＰＥＮＡＮＡXYyDlw9Xk7
783Please respect copyright.ＰＥＮＡＮＡRpBvk7qQIg
Ref1:https://www.pnas.org/content/116/30/15122783Please respect copyright.ＰＥＮＡＮＡPvFPMX3G2Q
8964 copyright protection779ＰＥＮＡＮＡo5nh5o1tUI 維尼

216.73.216.229